Both clinicians and patients frequently claim that depressed patients "self-medicate" their depression with alcohol, and primary depression with secondary alcoholism probably accounts for 5-10% of the alcoholic population. While self-medication alone is clearly not a sufficient explanation for psychiatric patients' addictions, the self-medication hypothesis has important implications for patient care and for our understanding of the pathophysiology of mood disorders. For example, a patient's choice of psychoactive substance may provide a clue to the neurochemistry underlying his symptoms. We are conducting a pilot study designed to elucidate the characteristics of primary depressives who claim to self-medicate with alcohol. Our index group consists of patients who meet DSM-III-R criteria for major depressive disorder (MDD), and for alcohol dependence (AD). We compare them to two other clinical groups on a number of clinical and phenomenological measures. The two comparison groups consist of patients with NMD but no history of alcohol abuse or AD; and patients with a history of AD who have never had MDD. In conjunction with the above project, we have developed a questionnaire that asks about patients' use of alcohol, carbohydrates, and caffeine in response to specific depressive symptoms. We gave the questionnaire to a sample of patients with seasonal affective disorder (SAD). The SAD patients reported using each of the three substances in response to a specific profile of symptoms, and reported that each substance had a distinctive effect on their symptoms. We are currently administering the questionnaire to a sample of patients with MDD and AD.